4 static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
6 static char dirname[PATH_MAX];
11 snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
12 dir = opendir(dirname);
13 sprintf(hex, "%.2s", name);
17 while ((de = readdir(dir)) != NULL) {
18 if (strlen(de->d_name) != 38)
20 if (memcmp(de->d_name, name + 2, len-2))
22 memcpy(hex + 2, de->d_name, 38);
29 return get_sha1_hex(hex, sha1) == 0;
33 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
48 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
53 for (p = packed_git; p; p = p->next) {
54 unsigned num = num_packed_objects(p);
55 unsigned first = 0, last = num;
56 while (first < last) {
57 unsigned mid = (first + last) / 2;
58 unsigned char now[20];
61 nth_packed_object_sha1(p, mid, now);
62 cmp = memcmp(match, now, 20);
74 unsigned char now[20], next[20];
75 nth_packed_object_sha1(p, first, now);
76 if (match_sha(len, match, now)) {
77 if (nth_packed_object_sha1(p, first+1, next) || !match_sha(len, match, next)) {
78 memcpy(sha1, now, 20);
87 static int get_short_sha1(const char *name, unsigned char *sha1)
91 unsigned char res[20];
94 memset(canonical, 'x', 40);
96 unsigned char c = name[i];
100 if (c >= '0' && c <= '9')
102 else if (c >= 'a' && c <= 'f')
104 else if (c >= 'A' && c <='F') {
117 if (find_short_object_filename(i, canonical, sha1))
119 if (find_short_packed_object(i, res, sha1))
124 static int get_sha1_file(const char *path, unsigned char *result)
127 int fd = open(path, O_RDONLY);
132 len = read(fd, buffer, sizeof(buffer));
136 return get_sha1_hex(buffer, result);
139 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
141 static const char *prefix[] = {
150 if (len == 40 && !get_sha1_hex(str, sha1))
153 for (p = prefix; *p; p++) {
154 char *pathname = git_path("%s/%.*s", *p, len, str);
155 if (!get_sha1_file(pathname, sha1))
162 static int get_sha1_1(const char *name, int len, unsigned char *sha1);
164 static int get_parent(const char *name, int len,
165 unsigned char *result, int idx)
167 unsigned char sha1[20];
168 int ret = get_sha1_1(name, len, sha1);
169 struct commit *commit;
170 struct commit_list *p;
174 commit = lookup_commit_reference(sha1);
177 if (parse_commit(commit))
180 memcpy(result, commit->object.sha1, 20);
186 memcpy(result, p->item->object.sha1, 20);
194 static int get_nth_ancestor(const char *name, int len,
195 unsigned char *result, int generation)
197 unsigned char sha1[20];
198 int ret = get_sha1_1(name, len, sha1);
202 while (generation--) {
203 struct commit *commit = lookup_commit_reference(sha1);
205 if (!commit || parse_commit(commit) || !commit->parents)
207 memcpy(sha1, commit->parents->item->object.sha1, 20);
209 memcpy(result, sha1, 20);
213 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
218 /* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */
219 if (len > 2 && name[len-2] == '^' &&
220 name[len-1] >= '0' && name[len-1] <= '9') {
221 parent = name[len-1] - '0';
224 else if (len > 1 && name[len-1] == '^') {
231 return get_parent(name, len, sha1, parent);
233 /* "name~3" is "name^^^",
234 * "name~12" is "name^^^^^^^^^^^^", and
235 * "name~" and "name~0" are name -- not "name^0"!
238 for (cp = name + len - 1; name <= cp; cp--) {
240 if ('0' <= ch && ch <= '9')
246 if (!parent && *cp == '~') {
247 int len1 = cp - name;
249 while (cp < name + len)
250 parent = parent * 10 + *cp++ - '0';
251 return get_nth_ancestor(name, len1, sha1, parent);
254 ret = get_sha1_basic(name, len, sha1);
257 return get_short_sha1(name, sha1);
261 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
262 * notably "xyz^" for "parent of xyz"
264 int get_sha1(const char *name, unsigned char *sha1)
266 return get_sha1_1(name, strlen(name), sha1);